Previously known semiconductor laser treatment devices have been described in, for example, Japanese Patent Publication (Toku-kai) Sho 58-86178, 58-89278, and 59-105445. However, this prior art had the following defects which needed improvement.
The first problem involved the means of regulating the degree of convergence of the laser beams emitted from the multiple semiconductor lasers. In other words, the luminous output of the semiconductor lasers used today is restricted. To obtain the intensity of beam output required for use in medical treatment, multiple semiconductor lasers have to be combined, and the laser beams from them focused at a particular point. To achieve this, laser beams are emitted from multiple semiconductor lasers, and the output beams are aligned in parallel by the corresponding first lenses, and are made to fall on the second lens at right angles and at a specified place on its circumference. However, because the quality of the laser beam varies, and because the laser beam emission position, ie the part emitting the radiated beam, may be positioned slightly higher or lower, or further to the front or rear, and the angle of laser beam emission varies, it is difficult to obtain the desired angle of incidence of the laser beams without adjusting the relative positions of the semiconductor laser, first lens and second lens. Various adjustments are then required, such as the positioning of the semiconductor lasers and the corresponding first lenses at the specified circumference in relation to the second lens, within a precision of several tens to several microns, then aligning the emission points of the semiconductor laser beams with the focuses of the first lens so that the laser beams are emitted in parallel at the required degree by the first lens, and at the same time making the optical axis of the parallel beams radiated from the first lens roughly parallel with the lens axis of the first lens (in other words, the radiation angle of the beam emitted from the first lens--the angle made by the beam axis of the emitted light and the axis of the first lens--is approximately zero). In addition when the laser emission point of the said semiconductor lasers cannot be properly adjusted with the focuses of the first lenses, and the optical axis of the parallel beams is slightly inclined towards the lens axis of the first lenses, these inclined parallel beams must be made to strike the second lens at right angles and in a specified position. Because these adjustments have to be made to within several microns precision, previously known semiconductor laser treatment devices required extremely sophisticated techniques, and have the disadvantage that the semiconductor laser treatment device is difficult to assemble initially, and all subsequent adjustments during maintenance, inspection, and replacement of the semiconductor lasers require the device to be returned to the manufacturer for specialist handling.
The second disadvantage of prior art is that during a power check of the laser beam, there must be enough space to place a separate power check unit alongside the semiconductor laser treatment device. Where no space is available, a separate table must be provided alongside the semiconductor laser treatment device, involving some inconvenience. This method has another disadvantage in that the results of meter reading will vary somewhat since the operator is required to make the final judgement on whether the semiconductor laser treatment unit is usable or not from the movement of the meter which converts the laser beam to an electric signal.
The third disadvantage is that because the laser radiation device is operated by hand to radiate beams using a power check photo-sensor, the operator radiating the laser beam estimates the central point of the photo-sensor by eye, leading to laser beams radiated diagonally to the photo-sensor or at different distances from the photo-sensor. This causes differences in the receiving of the laser beams and thus to variations in the measurements, giving rise to inconsistencies in the results of power checks.
Fourthly, to the applicant's knowledge, prior art using touch sensors indicate the operation of the touch sensor by simultaneously sounding a buzzer or displaying a lamp which shows "In use". Even when the touch sensor is simply in contact with the patient's skin and laser beams are not actually being emitted, both patients and operators may think that laser beams are being emitted, thus posing a problem during treatment.
The fifth problem with prior art is because the time display which indicates the laser beam emission time operates by counting backwards from a preset time to zero, where treatment extends past the initial preset time and the device is re-operated, there is no way of calculating the total emission time aside from noting the previous emission time on a piece of paper and adding it to the new time.
The sixth disadvantage of the prior art is that because the touch sensor is fixed, some patients feel an unpleasant sensation when it is pressed on the treatment area.